CVE-2026-63984Network attack vector

Remote kernel memory corruption via RPL header overflow

Published Jul 19, 2026 · Updated Jul 19, 2026

Integer overflow in Linux Kernel IPv6 RPL handling allows remote attackers to corrupt kernel memory via a crafted routing header. ipv6_rpl_srh_decompress stores a 256-byte-unit result in an 8-bit hdrlen field, wraps it to zero, and makes compressed and decompressed regions overlap. Exploitation requires rpl_seg_enabled on an RPL router or gateway and can disclose memory, alter forwarded data, or crash the kernel.

CVSS severity9.8
Critical
EPSS probability0.51%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Integer overflow in Linux Kernel IPv6 RPL handling allows remote attackers to corrupt kernel memory via a crafted routing header. ipv6_rpl_srh_decompress stores a 256-byte-unit result in an 8-bit hdrlen field, wraps it to zero, and makes compressed and decompressed regions overlap. Exploitation requires rpl_seg_enabled on an RPL router or gateway and can disclose memory, alter forwarded data, or crash the kernel.

The record

CVE
CVE-2026-63984
Published
Jul 19, 2026
Updated
Jul 19, 2026
Vendor
The Linux Kernel Organization
Product
Linux Kernel
Classifications
CWE-190
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jul 19, 2026CVE publishedPublication date reported by the CVE source.
  2. Jul 19, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=5.7
  2. Affected versionversion=8610c7c6e3bd647ff98d21c8bc0580e77bc2f8b3 <3618b34942b76471d044369bfd30d58c39068bf1
  3. Affected versionversion=8610c7c6e3bd647ff98d21c8bc0580e77bc2f8b3 <6fe1cb312038516cb4d9fa089d700af7059f1a64
  4. Affected versionversion=8610c7c6e3bd647ff98d21c8bc0580e77bc2f8b3 <75b3680047bf09af8e7e471a7a6ddf2ce5847f56
  5. Affected versionversion=8610c7c6e3bd647ff98d21c8bc0580e77bc2f8b3 <97e06791368c01f0ad2a4b3269c2abe19485ca32
  6. Affected versionversion=8610c7c6e3bd647ff98d21c8bc0580e77bc2f8b3 <9d5e7a46a9f6d8f503b41bfefef70659845f1679
  7. Affected versionversion=8610c7c6e3bd647ff98d21c8bc0580e77bc2f8b3 <c0487a9c1e116cf349e2d1f302d9019670460858
  8. Affected versionversion=8610c7c6e3bd647ff98d21c8bc0580e77bc2f8b3 <de02fc049352af5a9595f015511222d0a85c326b
  9. Affected versionversion=8610c7c6e3bd647ff98d21c8bc0580e77bc2f8b3 <fd238c51b0fa5390cceca9f1ac5a9ffda8063eed

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

The Linux Kernel Organization · Linux Kernelversion=5.7; version=8610c7c6e3bd647ff98d21c8bc0580e77bc2f8b3 <3618b34942b76471d044369bfd30d58c39068bf1; version=8610c7c6e3bd647ff98d21c8bc0580e77bc2f8b3 <6fe1cb312038516cb4d9fa089d700af7059f1a64; version=8610c7c6e3bd647ff98d21c8bc0580e77bc2f8b3 <75b3680047bf09af8e7e471a7a6ddf2ce5847f56; version=8610c7c6e3bd647ff98d21c8bc0580e77bc2f8b3 <97e06791368c01f0ad2a4b3269c2abe19485ca32; version=8610c7c6e3bd647ff98d21c8bc0580e77bc2f8b3 <9d5e7a46a9f6d8f503b41bfefef70659845f1679; version=8610c7c6e3bd647ff98d21c8bc0580e77bc2f8b3 <c0487a9c1e116cf349e2d1f302d9019670460858; version=8610c7c6e3bd647ff98d21c8bc0580e77bc2f8b3 <de02fc049352af5a9595f015511222d0a85c326b; version=8610c7c6e3bd647ff98d21c8bc0580e77bc2f8b3 <fd238c51b0fa5390cceca9f1ac5a9ffda8063eed

Published CVSS scores

9.8Linux kernel CNACVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-190Integer Overflow or Wraparound

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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